Many cancer cells express higher levels of mitochondrial Hsp90 and TRAP1, up-regulate the associated signaling pathways and depend on them for survival, (e.g. TRAP1 promotes neoplastic growth through inhibiting succinate dehydrogenase (104)) making them vulnerable to drugs that inhibit these molecules, normal cells have lower expression levels of mtHsp90, thus less susceptible to drugs targeting mtHsp90. This evidence concerns the gene HSP90AA1 and cancer.